What Is Toxic Megacolon?

The large intestine is the last section of your digestive tract and includes your appendix, colon, and rectum. The large intestine completes the digestion process by absorbing water and passing waste through to the anus.

Certain conditions can cause the large intestines to malfunction. One such condition is toxic megacolon or megarectum. “Megacolon” is a general term that is used to mean the dilation of the colon. “Toxic megacolon” is a term meant to express the seriousness of the condition.

Toxic megacolon is a rare, life-threatening widening of the large intestine that occurs within a few days. It is a complication of inflammatory bowel diseases.

What Causes Toxic Megacolon?

The root causes of toxic megacolon are inflammatory bowel diseases (IBDs). Inflammatory bowel diseases cause swelling and irritation in parts of your digestive tract. These diseases can be painful and can cause permanent damage to your large and small intestines. Examples of IBDs include ulcerative colitis and Crohn’s disease.

Toxic megacolon occurs when inflammatory bowel diseases cause the colon to expand, dilate, and distend. When this happens, the colon is unable to remove gas or feces from the body. If gas and feces build up in the colon, your large intestine may rupture (break open).

Rupture of your colon is a life-threatening condition. If your intestines rupture, bacteria that are normally present in your intestine are released into your abdomen, which can cause a serious infection and even death.

It is important to note that there are other types of megacolon. Examples include:

pseudo-obstruction megacolon

colonic ileus megacolon

congenital colonic dilation

Although these conditions can result in expansion of and damage to the colon, they are not caused by inflammation or infection.

What Are the Symptoms of Toxic Megacolon?

When toxic megacolon occurs, it will result in the rapid expansion of the large intestines. Symptoms of the condition may come on suddenly and may include:

abdominal pain

bloating of the abdomen (distention)

abdominal tenderness

fever

rapid heart rate

shock

bloody diarrhea

frequent diarrhea

painful bowel movements

The symptoms of toxic megacolon represent a life-threatening condition. If these symptoms develop, you should seek medical attention.

How Is Toxic Megacolon Diagnosed?

If you develop symptoms of toxic megacolon, your doctor can confirm your diagnosis through a physical exam and other tests. He or she will ask you about your health history and whether or not you have any inflammatory bowel diseases. Your doctor will also check to see if you have a tender abdomen and if bowel sounds can be heard through a stethoscope placed on your abdomen.

If your doctor suspects that you have developed toxic megacolon, he or she may order additional testing to confirm this diagnosis. Additional tests used to confirm this diagnosis include:

abdominal X-ray

blood tests such as a complete blood count (CB) and blood electrolytes

How Is Toxic Megacolon Treated?

The treatment of toxic megacolon typically involves surgery. If you develop this condition, you will be admitted to the hospital. You will be given fluids to prevent shock from occurring. Shock occurs when an infection in the body causes your blood pressure to decrease rapidly. Shock is a life-threatening condition.

Once your blood pressure is stable, you will need surgery to correct toxic megacolon. In some instances, toxic megacolon may produce a tear or perforation in the colon. This tear must be repaired to prevent bacteria from the colon from entering into the body.

Even if a perforation does not result, the tissue of the colon may be weakened or damaged and may need to be removed. Depending on the extent of the damage, you may need to undergo a colectomy. This procedure involves a complete removal of the colon.

Following surgery, you will be given antibiotics. These medications will help to prevent a serious infection known as sepsis. Sepsis causes a severe reaction in the body that can be life-threatening.

What Is the Long-Term Outlook for People With Toxic Megacolon?

If you develop toxic megacolon and promptly seek treatment, your long-term outlook will be good. Seeking emergency medical treatment for this condition will help prevent complications including:

perforation of the colon

sepsis

shock

If complications of toxic megacolon occur, your outlook may not be as good. Complete removal of the colon may require you to have an ileostomy or ileoanal pouch anal anastomosis (IPAA) put in place. These devices will remove feces from your body after your colon is removed.

How Can You Prevent Toxic Megacolon?

Toxic megacolon is a complication of inflammatory bowel diseases. If you have one of these conditions, you should follow your doctor’s advice. This may include making lifestyle changes and taking certain medications. Following your doctor’s advice will help control the symptoms of IBD and reduce the likelihood that you will develop toxic megacolon.